Mounting structure for shaver blade



Sept. 4, 1962 J. F. WAHL 3,052,022

MOUNTING STRUCTURE FOR sHAvER BLADE Filed DeC. 3, 1959 INVENToR. mi2/w?F' Wahl aegwM/m www Horner/s UnitedStates Patent O 3,052,022 MGUNTINGSTRUCTURE FOR SHAVER BLADE John F. Wahl, Sterling, Ill., assigner toWahl Clipper Corporation, Sterling, Ill., a corporation of IllinoisFiled Dec. 3, 1959, Ser. No. 857,180 2 Claims. (Cl. 30-43) Thisinvention relates to mounting structure for a shaver blade, and moreparticularly to a fixed outer shaver blade for an electric shaverandmeans for mounting this shaver blade on the casing of the electricshaver.

This application is a continuation-impart application based on my prior,copending application for Electric Shaver Apparatus, Serial No. 753,773,filed August 7, 1958, now abandoned.

' In order for an electric shaver to function properly, the fixed orouter shaver bl-ade must have proper bearing contact with the inner ormovable blade over their entire cutting region. Since the outerblade isformed from thin sheet material, it is subject to permanent deformationby accidental blows, and such deformation could destroy this bearingcontact between the blades, thus adversely affecting operation of theshaver. Heretofore, many of the outer shaver blades either werepermanently mounted in a blade guard or they were attached thereto by acomplicated mounting structure. This ,arrangement was undesirablebecause the shaver operation could not be examined or tested properlyafter installation of the blade guard. In addition, the added difficultyinvolved in mounting the fragile outer blade on the blade guard resultedin an objectionable increase in the cost of production.

Furthermore, during production, and when in consumer use, itoccasionally happened that the outer blade was accidentally deformedafter it had been connected to the blade guard. This often required boththe blade and the blade guard to be discarded. It is apparent that suchlosses could be minimized if the outer blade and the blade guard werecompletely independent of each other.

Therefore one of the objects of this invention is to provide a shaver inwhich the fixed outer blade and the blade guard are independent of eachother and are separately mounted on the casing of the electric shaver.

Another disadvantage with the outer blades of prior Shavers was that theouter blade could be mounted on the shaver casing with either surface inposition to Contact the skin. This is undesirablebecause the fixed outerblades are designed to work only when a particular surface is in contactwith the skin. Since the opposed surfaces of the fixed outer blade aresimilar in appearance, it was possible for the lblade to be mounted onthe shaver casing with the wrong surface out so that the manufacturer orthe user had togo to the trouble and expense of removing the blade andthen reinstalling it correctly. What is needed, therefore, and comprisesanother object of this invent-ion is a fixed outer blade for an electricshaver which can be mounted on the shaver in only Oneway. Y

Besides these considerations, the casings of man Shavers are formed froma plastic material which may vary dimensionally due to moldingconditions. In the past this has caused the fragile fixed outer blade tobuckle or tear. What is needed, therefore, and comprises another objectof this invention, is a fixed outer blade which when mounted on theshaver casing or housing can accommodate Variations in the size of theshaver housing without becoming deformed or torn.

j 3,052,022 Patented Sept. 4, 1962 Since the fixed outer blade isfragile, it may have to be replaced after `a period of time. For thatreason the blade must be removably mounted on the shaver casing. At thesame time, because the blade is bent arcuately and is under tension whenit is mounted on the casing there is a danger that during the mountingoperation the blade can spring off the casing and cause injury or elsebecome damaged. What is needed therefore and comprises still anotherobject of this invention is a self locking resilient blade for anelectric shaver Iwhich is removably mounted on the shaver casing. Y

' Safety is another important consideration in the manufacture ofelectric Shavers. This is particularly important because the fixed outerblade is generally formed from thin sheet metal which contacts the skinduring use. This arrangement raises the possibility of electric shockunless precautions are taken. Therefore, another object of thisinvention is to provide a mounting which in addition to holding thefixed outer 4blade on the casing provides electrical insulation betweenthe fixed outer blade and the motor parts of the shaver.

These and other objects of this invention will become more apparent whenread in the light of the accompanying drawing and specification wherein:

FIG. 1 is a side elevational View of the front end portion of anelectric shaver showing a fixed outer blade and blade guard;

FIG. 2 is an end elevational View of the blade guard installed on anelectric shaver;

FIG. 3 is a perspective view ofthe shaver head showing the fixed outerblade in dotted lines;

FIG. 4 is a plan view of the xed outer blade before it is installed onthe shaver, and

FIG. 5 is an enlarged side View partially in section showing details ofthe way the fixed outer blade is mounted on the shaver casing;

FIG. 6 is an enlarged plan view of the fixed outer blade showingself-locking tangs in greater detail.

Referring now to the drawing, an electric shaver indicated generally bythe reference numeral 10 includes a casing 12 formed from a moldableinsulating material such as nylon. Casing 12 is formed in two sections14 and 16, see FIG. 3, and a fixed outer blade 18 is mounted on the endsof these sections as best shown in FIG. 5. A portion of this bladerconstituting cutting region 32 is in slidable engagement with a portionof an inner movable cut- -ting blade 19 (FIG. 5). The casing sectionsmay be held together Iby means of a blade guard 20 which also cooperatesto secure the fixed outer blade to the front of the casing as shown inFIG. 1 and described more fully below.

As seen in FIGS. 3 and 5, casing sections 14 and 16` have spaced taperedor converging surfaces 22 and 24 at the top end portion 11 of theshaver. Three cylindricai projecting members or pins 26 and one non-jcylindrical pin 27 are integrally formed and molded with the casing 12and extend outwardly from the end portions of surfaces 22 and 24. Asseen in FIG. 5, these pins are transverse to the plane defined byjunction 28 of the sides of the casing sections and are substantialyopposite to each other on the opposite sides of the casing. Thisarrangement defines an acute rearwardly facing angle 30' (FIG. 5) at thejunction between each projecting member 26Y and 27 and the tangent tothe converging surfaces at that point.

Fixed outer blade l'18, as seen in FIG. 4, is normally 3 planar andrectangular in shape before it is mounted on the casing. This blade isformed from thin resilient sheet metal and is provided with a perforateportion constituting a cutting region 32. Four projecting memberreceiving openings 34, 36, 38 and 40 are formed in the sheet metal andas illustrated, are disposed on the corners of the periphery of arectangle which is deiined by imaginary lines connecting the openings.

Projecting member 27 is irregular, e.g. semi-circular in cross section,see FIG. 3, and this member is adapted to extend through acorrespondingly shaped opening 34 in fixed outer blade 18 to orient theblade on the casing so the proper surface invariably will be on theoutside and thus in position to contact the skin.

Openings 36 and 38 are elongated to provide compensation for variationsin the spacings between the openings and between the projecting memberswhich are received within the openings. Thus, buckling of blade 18 isavoided despite such variations. In other words, the elongated holespermit a relaxation of production standards since a larger variationbetween the spacings of the projecting members on the casing and theopenings in the fixed outer blade can be tolerated.

As shown in FIG. 6, tangs 35, l37 and 39 are formed in openings 34, 36and 38, and these tangs cooperate, as

will be seen, to establish a self-locking relationship between blade 18and the projecting members.

To mount blade 18 onto the casing 12, the blade is iiexed as shown inFIG. 5 so that central or perforate cutting region 32 is arcuate incross section. The ends of the blade are pressed against thesubstantially opposed converging surfaces 22 and 24 so that all fourprojecting members 26 and 27 can pass through the openings 34, 36, 38and 40. In order for this to happen, the blade 18 must be oriented sothat projecting member 27, which is irregular or semi-circular in crosssection, can pass through the correspondingly shaped opening 34. If theblade 18 is not properly oriented, a cylindrical projecting member 26will be aligned with the opening 34, but it will be too large to passthrough it.

As stated above, projecting members 26 and 27 form a rearwardly facingacute angle 30 with a tangent to the converging surfaces 22 and 24 atthe junction of the projecting members 26 and 27 and the convergingsurfaces. The magnitude of the acute angle 30 and the length of theprojecting members and the converging surfaces are selected so that asthe arcuately exed resilient blade 18 tends to move back toward itsplanar unstressed form, tangs 35, 37 and 39 in openings 34, 36 and 38bite into the associated projecting members 26 and 27 to removably holdthe blade onto the casing, see FIG. 5.

It is noted that this mounting avoids any metal to metal contact betweenthe fixed outer blade and any part of the shaving mechanism (other thanmovable blade 19 which likewise is insulated) thus greatly reducingshock hazard.

After outer blade 18 is mounted on the casing, it is additionally lockedthereon by blade guard 20. This blade guard is formed from an insulatingand preferably moldable slightly resilent material. As seen in FIGS. 1and 3, blade guard 20 comprises spaced parallel upstanding ears 21 and23 which are connected together by converging connecting portions 25.

Each ear 21 and 23 of the blade guard may be provided with an opening29, see FIG. 2, to receive a locking abutment 31 which is integrallyformed and molded with casing 12.

'Ihe inner surfaces of converging portions 25 of the blade guard areprovided with grooves (not shown) and when blade guard 20 is forced overend 111 of the casing, the grooves on the inner surfaces of the bladeguard pass over and embrace the outer ends of the projecting members 26and 27. This positively locks outer blade 18 onto the casing, and theinner surfaces of portions 25 overlie covering surfaces 22 and 24 on thecasing with portions of blade 1 8 therebetween.

In addition, the blade guard 20 is positioned so openings 29 in ears 21and 23' are aligned with the locking abutments 31 whereby the bladeguard may be snapped into place on the casing and held there. Thisarrangement also locks the casing sections 14 and 16 together, thusgiving the blade guard an added function.

This invention may be embodied in other forms without departing from thespirit or essential characteristics thereof as set forth inthe claims,and the present embodiment is therefore to be considered as illustrativeand not restrictive and it is intended to include all changes which comewithin the scope and range of the claims.

I claim:

l. In a dry shaver:

a casing having opposed wall portions converging toward each othertoward one casing end, said wall portions formed of insulating material;

spaced projecting members attached to and extending outwardly from saidwall portions and deiining therebetween acute angles on the sides of themembers away from said casing end;

at least one of said projecting members having cross sectional shapedifferent than the other members;

a xed outer blade formed of initially flat perforate resilient sheetmaterial having projecting member receiving openings therein, said outerblade iiexed to an arcuate cross section and mounted on said casing withsaid projecting members extending through said projecting mem-berreceiving openings whereby said `blade tends to be locked to said casingby virtue of said acute angles between said projecting members and saidwall portions;

corresponding openings adjacent opposite edges of said blade elongatedto compensate for dimensional variations in the spacing of said spacedprojecting members;

the opening for said differently shaped projecting member havingcorresponding shape to insure proper orientation of said blade;

an opening adjacent each edge of said blade having a marginalirregularity providing a deformable tang gripping the projecting memberextending through said opening whereby said blade additionally is lockedin position on said casing; and

a blade guard detachably secured to said casing end and effective toprevent disengagement between said blade and said projecting members,said blade guard covering the edges of said blade and having a centralopening exposing a perforate portion of said blade.

2. In a dry shaver:

a casing having opposed wall portions formed of insulating material;

spaced projecting members attached to and extending outwardly from saidwall portions;

at least one of said projecting members having cross sectional shapedifferent than the other members;

a fixed outer blade formed of initially flat perforate resilient sheetmaterial having projecting member receiving openings therein, said outerblade iiexed to an arcuate cross section and mounted on said casing withsaid projecting members extending through said projecting memberreceiving openings;

corresponding openings adjacent opposite edges of said blade elongatedto compensate for dimensional variations in the spacing of said spacedprojecting members;

the opening for said differently shaped projecting member havingcorresponding shape to insure proper orientation of said blade;

an opening adjacent each edge of said blade having a marginalirregularity providing a deformable tang gripping the projecting memberextending through said opening whereby said blade is locked in positionon said casing; and

a blade guard detachably secured to said casing end and 5 eective toprevent disengagement between said blade and said projecting members,said blade guard covering the edges of said blade and having a centralopening exposing a perforate portion of said blade.

References Cited in the le of this patent UNITED STATES PATENTS 387,260Rush Aug. 7, 1888 6 Lipe July 2, 1889 Unbany Mar. 22, 1938 Picard Nov.20, 1945 Jepson Nov. 14, 1950 Streng July 17, 1951 Palson Nov. 6, 1951Tuchel Oct. 2, 1956 Braun et al. Oct. 20, 1959

